mongotail is a command line tool to outputs any operation from a Mongo
database in the standard output. You can see the operations collected by the
database profiler from a console, or redirect the result to a file, pipes
it with grep or other command line tool, etc.

The syntax is very similar to mongo client, and the output, as like
tail command will be the latest 10 lines of logging.

But the more interesting feature (also like tail) is to see the changes
in “real time” with the -f option, and occasionally filter the result
with grep to find a particular operation.

Syntax

Usage:

mongotail [db address] [options]

“db address” can be:

foo

foo database on local machine (IPv4 connection)

192.169.0.5/foo

foo database on 192.168.0.5 machine

remotehost/foo

foo database on remotehost machine

192.169.0.5:9999/foo

foo database on 192.168.0.5 machine on port 9999

“[::1]:9999/foo”

foo database on ::1 machine on port 9999 (IPv6 connection)

Optional arguments:

-u USERNAME, --username USERNAME
username for authentication
-p PASSWORD, --password PASSWORD
password for authentication. If username is given and
password isn't, it's asked from tty
-b AUTH_DATABASE, --authenticationDatabase AUTH_DATABASE
database to use to authenticate the user. If not
specified, the user will be authenticated against the
database specified in the [db address]
-n N, --lines N output the last N lines, instead of the last 10. Use
ALL value to show all lines
-f, --follow output appended data as the log grows
-l LEVEL, --level LEVEL
specifies the profiling level, which is either 0 for
no profiling, 1 for only slow operations, or 2 for all
operations. Or use with 'status' word to show the
current level configured. Uses this option once before
logging the database
-s MS, --slowms MS sets the threshold in milliseconds for the profile to
consider a query or operation to be slow (use with
`--level 1`). Or use with 'status' word to show the
current milliseconds configured
-m, --metadata extra metadata fields to show. Known fields (may vary
depending of the operation and the MongoDB version):
millis, nscanned, docsExamined, execStats, lockStats ...
-i, --info get information about the MongoDB server we're connected to
-v, --verbose verbose mode (not recommended). All the operations will
printed in JSON without format and with all the
information available from the log
--ssl creates the connection to the server using SSL
--sslCertFile SSL_CERT_FILE
certificate file used to identify the local connection
against MongoDB
--sslKeyFile SSL_KEY_FILE
private keyfile used to identify the local connection
against MongoDB. If included with the certfile then
only the sslCertFile is needed
--sslCertReqs SSL_CERT_REQS
specifies whether a certificate is required from the
other side of the connection, and whether it will be
validated if provided. It must be any of three values:
0 (certificate ignored), 1 (not required, but
validated if provided), 2 (required and validated)
--sslCACerts SSL_CA_CERTS
file that contains a set of concatenated
"certification authority" certificates, which are used
to validate certificates passed from the other end of
the connection
--sslPEMPassword SSL_PEM_PASSPHRASE
password or passphrase for decrypting the private key
in sslCertFile or sslKeyFile. Only necessary if the
private key is encrypted
--sslCrlFile SSL_CRLFILE
path to a PEM or DER formatted certificate revocation
list
-h, --help show this help message and exit
-V, --version show program's version number and exit

Enabling Database Profiling and Showing Logs

You have to activate first in the current database the
profiler,
so MongoDB will capture all the activity in a special document that is read by Mongotail.

You can achieve this with -l,--level option. For example, if you want to see the logs
from MYDATABASE, first you have to execute this:

To Connect with SSL or a remote Mongo instance, check the options with mongotail --help command.

NOTE: The level chosen can affect performance. It also can allow the
server to write the contents of queries to the log, which might have
information security implications for your deployment. Remember to setup your
database profiling level to 0 again after debugging your data:

$ mongotail MYDATABASE -l 0

Installation

You can install the latest stable version with pip in your environment with:

$ pip install mongotail

Execute this command with administrator/root privileges.

You have to be installed pip tool first. In Debian/Ubuntu Linux
distribution you can install it with (also with root privileges):